Destruction behaviors of n-nitrosodiethylamine, benzidine, and diethylaniline were studied by the investigation of destruction rates and products in supercritical water(SCW) with and without oxygen. The experimental conditions included a temperature rage from 380℃ to 500℃ and a SCW density of 0.25 g/mL. A batch reactor system was used for the experiments. The important characteristics of the destruction behaviors can be summarized as follows. First, the destruction of n-nitrosodiethylamine exhibited fast kinetics via thermohydrolysis as well as oxidation. Such observation of the fast kinetics may be generally applicable to the nitrogen-containing compounds of no aromatic ring structure. Furthermore, the fast thermohydrolysis kinetics should separately be investigated and may be taken advantage of for the efficient destruction of these compounds. Second, the slow destruction kinetics of benzidine as compared to those of n-nitrosodiethylamine indicates that the nitrogen-containing aromatic compounds are more resistant in SCW conditions as compared to chlorinated organic compounds. Third, the very fast destruction kinetics of diethylaniline indicated that when an additional substitute such as an alkyl group is present in the nitrogen containing aromatics, the overall destruction kinetics of the compound primarily depends on the refractiveness of the substituted group. Fourth, benzene ring has a fundamental impact on the completeness of the destruction of these compounds in SCW.